Ski



Oct; 7 T. F. SALERNO 3,534,972

SKI

Filed Oct. 11, 1968 INVENTOR. THOMAS F. SALERNO ATTORNEY United StatesPatent 3,534,972 SKI Thomas F. Salerno, 51 Sherman Ave., Plainview, N.Y.11802 Filed Oct. 11, 1968, Ser. No. 766,727 Int. Cl. A63c /04 U.S. Cl.280-1113 7 Claims ABSTRACT OF THE DISCLOSURE A snow ski formed with acentral groove extending from a short distance behind the front tip ofthe ski and continuing rearwardly over the remaining length of the ski.The groove becoming progressively wider in the lateral direction anddeeper in the vertical direction and opening through the top surface ofthe ski near the rear end thereof to divide the rear of the ski into twoseparate prongs which flex independently.

THE PRIOR ART Many skiers, even including some who are relativelyexperienced, have found that control is a problem in the sport of snowskiing, and that such problems on occasion can lead to spills andpossible serious injury. The factors which determine the degree ofcontrol which a skier can obtain, include the capacity of the skis toconform flexibly to uneven snow contours, to bite into the snow onturns, to develop a rail-like engagement with the snow on straightaways,and to generate lift, particularly at the rear of the ski.

The problem of flexible accommodation to uneven surfaces requires thatthe ski be flexible with respect to both its longitudinal and itstransverse axes. In addition, it is desirable that different parts ofthe ski be able to flex independently of each other. Prior art skis havenot had two-axis flexibility, nor have they exhibited the capacity forindependent fiexure.

Prior art devices have used grooves in the underside of the ski toprovide a rail-like engagement with the snow, and to provide extralongitudinal biting edges which are helpful 0n turns. But in the pastsuch ski grooves have not been optimally shaped to provide extra lift,particularly at the rear of the ski. Also, it was not heretoforerealized that the configuration of such a groove can be selected toachieve multi-axis flexibility and independent flexure of the variousparts of the ski.

SUMMARY AND OBJECTS OF THE INVENTION It is therefore a general object ofthis invention to provide a snow ski which achieves greater control andstability. More specifically, an object of the invention is to provide aski which is more flexible, particularly about both the longitudinal andtransverse axes of the skis. Another objective of the invention is toprovide a ski, the parts of which can flex independently of each other,so as to conform to uneven surface contours. Another objective is toprovide an improved underside groove for a ski which, in addition toproviding a rail-like engagement with the snow surface and extra bitingedges, also provides extra lift, particularly at the rear of the ski.

In accordance with the invention, these objectives are achieved byproviding a ski which has a forked rear end comprising two separateprongs which are able to flex independently of each other. Morespecifically, the invention contemplates a ski with a longitudinalcentral groove formed in the underside, which begins at a point near thefront or forward of the mid point of the ski and extends all the way tothe rear of the ski, widening and deepening as it approaches the rearend. Such a groove enables the ski to flex about its longitudinal axis,and also provides "ice additional biting edges to engage the snow. Thegroove has an elliptical cross-sectional shape which draws in snow fromthe surface and allows it to expand into the groove, thus giving the skiextra lift, particularly at the rear of the ski where the central groovewidens and deepens. Near the rear end of the ski the groove intersectsthe top surface of the ski to form a tapered notch dividing the ski intotwo separate rear prongs which can flex independently of each other forgreater stability. In addition, there are side grooves which run alongthe ski and the two separate prongs; these side grooves provideadditional biting edges and additional rail-like snow engagementsurfaces to the ski as a whole, and to the two separate prongsindividually.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a snowski in accordance with this invention, looking from the undersidethereof,

FIG. 2 is a bottom plan view of the same ski,

FIG. 3 is a longitudinal section of the same ski, taken along the lines3-3 of FIG. 2, looking in the direction of the arrows, and

FIG. 4 is a rear elevational view of the same ski.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The ski 10 of thisinvention is formed with a conventional upwardly curved forward tip 12,from which an elongated ski body 14 extends rearwardly, terminating in arear end 16. The upper ski surface 18 is provided with conventional skibindings, not shown, by means of which the ski is secured to the boot ofthe skier.

In accordance with this invention, the underside 20 of the ski is formedwith a long central groove 22 which.

begins at a point 24 not far behind the curved front tip 12 forward ofthe longitudinal mid point and extends longitudinally along the entireski 10 and opens through the rear end 16 thereof. As the groove 22extends rearwardly from the point 24, it becomes progressively wider,and also extends progressively deeper into the ski body 14. In FIGS. 1,2 and 4, for example, the reader can compare the relatively narrowlateral width of the groove 22 at forward location 22-1, with thesubstantially greater lateral width of the groove at rearward location22-2. The relatively small vertical depth of the groove at forwardlocation 22-1 can also be compared to FIGS. 3 and 4 to the substantiallygreater depth at rearward location 22-2. The further the groove 22approaches to the rear end 16 of the ski, therefore, the wider it getslaterally, and the deeper it extends upwardly into the ski body 14.

At location 22-2, the groove intersects the top surface 18 of the skisand thus merges into a notch 26 which completely divides the rear end 16into two separate legs or prongs 16-1 and 16-2. Note that the notch 26,starting from its apex at the point 22-2 where it merges with the groove22, also widens out as it extends rearwardly, to produce a substantialseparation between the legs or prongs 16-1 and 1'6-2.

By thinning out the middle of the ski body 14, the groove 22 enables thetwo longitudinal halves or portions of the ski body 14-1 and 14-2 oneither side of the groove 22 to flex more easily relative to each other,about the longitudinal center line of the ski 10. As a result, when theski passes over a snow contour which is curved transversely to thedirection of travel, the two ski halves 14-1 and 14-2 are able to flexrelative to each other about the longitudinal center line of the ski 10and thereby conform to the surface curvature. The two rear legs orprongs 16-1 and 16-2 are, of course, extensions of the two ski halves14-1 and 14-2 respectively, and are even more easily able to flexrelative to each other about the longitudinal axis, by virtue of theircomplete separation on either side of the notch 26.

An additional function served by the central groove 22 is that the edges28 of the groove 22 provide an additional capability for biting into thesnow surface, along with the outer edges 30 of the ski body 14. Thegroove 22 also provides a channel which becomes filled with a rail ofsnow, the engagement between the snow rail and the groove providingadditional engagement with the snow surface. Both of these factorscontribute tostability and control of the ski 10, much in the samemanner as did prior art grooves formed on the underside of a ski.

But in the case of the groove 22 of the present invention an additionalimportant effect takes place. Because of the fact that the groove widensand deepens as it extends towards the rear end 16, the snow which entersthe groove at point 24 subsequently expands both upwardly and laterallyas it proceeds along the remaining length of the groove. This expansionis particularly explosive, since the snow entering the groove 22 at theentrance point is first packed and compressed by the curved ski tip 12which initially rides thereover. Consequently, the sudden opportunity toexpand into the progressively widening and deepening volume along thelength of the groove 22 causes the packed snow to press outwardly andupwardly against the interior surface of the groove. This providesincreased lift over the length of the ski body 14, but the lift effectbecomes pregressively stronger toward the rear end 16 as the snowexpansion becomes progressively greater.

Note that the upward lift force provided by the expanding snow isexerted along the longitudinal center line of the ski 10, owing to thecentral location of the groove 22, a factor which contributes to lateralstability. Note also that the expanding snow pushes against the entirecurved surface of the groove 22, so that it presses sidewardly againstthe edges 28, as well as upwardly against the roof of the groove, thusincreasing lateral interaction between the snow and the ski and givingthe edges 28 a greater opportunity to bite into the snow surface.

The cross-sectional shape of the groove 22, as best seen in FIG. 4, iselliptical, preferably a 30 conical ellipse. The advantage of this shapeis that it provides a large surface area for the interior of the groove22 against which the expanding rail of snow can engage to provide alifting force and a lateral engagement. The same ellipticalconfiguration is maintained over the length of the groove 22, from itsstart at point 24 to the merger point 22-2 where the top of the ellipsebreaks through the upper surface 18 of the ski, but the scale of theellipse increases progressively from point 24 to point 22-2.

The beginning of the groove 22 at point 24 should be located wellforward of the skiers foot. Since the skiers foot is substantially inthe center of the ski and his toes extend some distance forward of thecenter, the point 24 should be located well toward the front of the skiand preferably just behind the curved tip 12 as shown. This gives theski body 14 greater flexibility in the area under and in front of theskiers foot, so that the ski can flex in response to foot and toemovements, a factor which contributes to the overall increase in controland stability.

The notch 26, by separating the prong 61-1 and 16-2, allows them to flexthrough an additional degree of freedom relative to each other. Forexample, one of these prongs can flex upwardly about the transverse axisof the ski 10, while the other can flex downwardly whenever this isrequired by unevenness in the snow surface. The

action is somewhat analogous to that of an independent rear wheelsuspension for an automobile, and it is recognized that this type ofautomotive suspension provides greater control and stability.

An additional feature of the invention involves the provision of sidegrooves 32 on either side of the central groove 22. These side grooves,like the central groove, provide additional biting edges for lateralengagement with the snow surface, and also draw in rails of snow whichincrease directional stability. Although this behavior in itself is notunusual, the provision of the side grooves 32 on either side of thecentral groove 22 provides a unique three-point suspension which,combined with all the other advantages of the present ski, givesunprecedented stability and control. This is particularly true since ineffect in each ski half 14-1 or 14-2 and its rear extension, prong 16-1or 162 respectively, has its own groove 32 to provide individual bitingedges and rail-like engagement with the snow. This enhances the effectof two independently movable ski elements, joined together only by aprogressively wider but thinner flexible webbing, i.e. that portion ofthe ski body 14 which is above the central groove 22.

Therefore, it will now be appreciated that the present inventionprovides a novel ski which demonstrates improved stability and controlin several important respects. In particular, the two halves of the skican flex relative to each other about the longitudinal axis of the ski,and they terminate in entirely separate rear prongs which are equivalentto an independent rear suspension in terms of their flexibility aboutthe transverse axis. The improved ski structure also provides additionalbiting edges to engage the snow surface, as well as a unique upward andoutward force exerted by the snow as it expands in those directions byvirtue of the progressively increasing volume of the central groove.

When skiing on soft or watery snow surface, there is often a loss ofstability and directional control because of the apparent absence ofcoherence of their molecules and the creation of a suction on theunder-surface of the skis as they move over such surface. However, inthe use of the present invention, such suction effect is obviated bypermitting the snow to expand up and out of the enlarging groove therebyproviding greater surface engagement between the ski and the softsurface beneath it to result in increased stability and directionalcontrol. On hard icy surfaces the edges 28 benefit stability anddirectional control by providing additional edges to cut into the ice.

Since the foregoing description and drawings are merely illustrative,the scope of protection of the invention has been more broadly stated inthe following claims; and these should be liberally interpreted so as toobtain the benefit of all equivalents to which the invention is fairlyentitled.

What is claimed is:

1. A ski comprising an elongated body,

a rearward end of said ski formed with a notch dividing said rearwardend into two separate legs each relatively movable on said ski,

said notch extending a distance forwardly of said rearward end with thelateral width of said notch tapering to an apex in the forwarddirection,

said notch extending from the bottom surface of said ski upwardly intothe vertical thickness of said ski, the vertical depth of said notchextending entirely through said vertical ski thickness over a length ofsaid ski from said rearward end to said apex, said notch merging at saidapex into a substantially central groove extending along said bottom skisurface forwardly from said apex, the veltical depth of said groovedecreasing forwardly from said apex,

the lateral boundaries of said notch merging into those of said centralgroove with the relative lateral spacing of the upper edges of saidnotch being less than the lower edges at which the same merge with saidcentral groove, and said central groove tapering forwardly.

2. A ski as in claim 1, wherein said central groove terminates at apoint well forward of the transverse median of said ski.

3. A ski as in claim .2, further comprising a pair of longitudinal sidegrooves formed on said bottom ski surface on opposite sides of saidcentral groove.

4. A ski as in claim 3, wherein said side grooves extend rearwardlyalong the underside of said separate legs.

5. A ski as in claim 1, wherein the cross-sectional shape of saidcentral groove is elliptical.

u. A ski comprising an elongated body,

a plurality of longitudinal relatively movable portions defined on theunderside of said ski body, said portions flexing relative to each otherabout the longitudinal center line of the ski body,

and a longitudinal groove separating said body into a plurality ofseparate relatively movable legs,

said movable portions each having surface engaging edges independent ofthe edges of the outer surfaces of said ski body, and said engagingedges of said portions moving independently of each other with theirrespective movable portions,

said movable portions being formed by a notch extending forward from therear of said body and defining an enlarged termination of said groove,

the lateral spacing of said notch being less at the upper edges thereofthan at the lower edges with said lateral spacings decreasing as thenotch extends forward from the rear of said body.

7. In a ski body,

a groove designed on the underside of said body extending longitudinallyfrom a point forward of the mid point of the length of said body to therear thereof to reduce the thickness of said body progressively from thebeginning of said groove to the rear of said body to define longitudinalportions extending along the sides of said body,

said longitudinal portions flexing relative to each other about thelongitudinal center of the ski body,

said longitudinal portions each having surface engaging edges definedalong the outer edge of said body and along said groove,

said longitudinal portions each terminating in separate legs movableindependently of the other on said ski body,

and said separate legs being formed by a notch tapering toward an apexextending forward from the rear of the ski body with the notch mergingwith said groove and the relative lateral spacing of the upper edges ofthe notch being less than the lower edges thereof merging with saidgroove.

References Cited UNITED STATES PATENTS 3,319,276 5/1967 Penney.

FOREIGN PATENTS 446,936 3/ 1948 Canada.

1,285,809 1/1962 France.

1,450,993 7/1966 France.

BANJAMIN HERSH, Primary Examiner M. L. SMITH, Assistant Examiner

